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1,702,346 w. HAHNEMANN ET AL SOUND TBANSEERRING HBANS Original Filed Nov. 4, 1921 01 m HM NW, 'ML 0mm Patented Feb. '19, 1929 UNITED WALTER HAHNEMANN, or xrrznnnn fnma man, up nnmnicn nnon'r AND BERN'EARD SETTEGA ST, OFJKIELL GERMANY, ASSIGNOBS I TO SIGNAL GESELL- SGHAF'J. MIT IBESGHRKNKTEB HAFTUNQ, OI IKIEL, GEBMANY.

i SOUND-TBANSFEBBING MEANS.

Original application filed November 4, 1921 Serial No. 612,946, and in Germany October 28, 1920. Divided and this application filed May 24, 1924. Serial No. 715,768. j

The present invention relates to means for transferring sound vibrations from one vibratory body to another and is' a division of our copending application, Ser. No. 512,946, filed 5 November 4:, 1921. The term vibratory body, as used herein, is intended to designate generically any body capable of executing physical vibrations, whether the body is formed of liquid, gas or' a solid, or combinations of these. The said 'copending applica tion is directed to the more general features of the new sound transferring means which we call the dual chamber; while the present divisional application is to be directed to a special form of the dual chamber invention in which one of the individual compartments is the auditory canal.

We will now describe our invention with reference to the accompanying drawing,'in

0 which the singlefigure shows the embodiment of the dual chamber principle where one individual compartment is formed by the auditory canal.

1 Referring more specifically to the drawing 10 indicates a casing or shell carrying the vibratory diaphragm 11 with which it forms a compartment 12. This compartment 12 represents one of the individual compartments of the dual chamber and is provided with the sound aperture or passage 13 leading there-' from. In the preferred embodiment of ourinvention, as shown, the casing or shell 10 1s m the form of a more orless shallow or flat funnel, closed at theoflared or.wide end by the diaphragm 11, and provided at the converged or narrow end with the sound passage or aperture l3.- When the diaphragm 11 is set invibration, sound vibrations are im parted to the fluid within the compartment 40 12, and pass out through the aperture or passa e 13. We have shown as a means for exciting the diaphragm .11, :an electromagnetic contrivance, of the coni entional type, formed of thefizmatur 14 the coil and fieldpieces 15 but, ilnwill be understood, of course, that thiscontrivance is'shown simply by way of example, and that the use ofv other suitable means forexciting the diaphragm is contemplated. In the particular embodiment shown the electro-magnetic device and the dia- 'phragm may be. considered as formingwhat is known as the receiver of an ordinarypresent-day telephone.

equally applicable for the auditory can compartment 12 forms with the auditory canal a dual chamber connected bythe sound passage or aperture 13. This dual chamber behaves or functions in the same manner as the form of dual chamber disclosed inour copending application, Ser. No. 512,946,

where both compartments of the dual chamher are constructed mechanically as a part of the sound transferring unit.

In accordance with the present invention,

the individual compartment 12 is made of v such predetermined size or volume with relation to the size or volume of the auditory canal 16 as to effect a predetermined change in the amplitude to force ratio of the sound vibrations passing from the diaphragm 11 to the organs of hearing. Where it is desired, for example, to increase the force anddecrease the amplitude of the vibrations of the diaphragm 11 during transference to the organs of hearing, the chamber 12 would be made larger than the auditory canal 16. To further improve the efliciency of sound transference, it may be found desirable to tune the dual chamber, consisting of the chamber 12, passage 13 and chamber 16, to the frequency of the sound vibrations being transferred. This tuning of the dual chamber may not, however, always be found necessary in practicing the inyention. i

While in the embodiment shown we have illustrated and described the means for trans-,

ferring sound vibrations from a vibratory diaphragm to the organs of hearing, a problem encountered in the ordinary present-day telephone, it is to be understood that the'present invention is not limited to the transference of. sound vibrations from a diaphragm to the ear. The invention is, for example,

ferring sound vibrations body of, air to the organs of hearing.

We claim I 1. Means for transferring sound vibrations to the organs of hearin'g, comprising a champurpose of transrom a vibratoryher adaptedto have'thevibrations imparted 4 thereto and having a sound passage leading therefrom, the chamber being designed to cooperate thI'Ogfh the sound passage with the to form a dual chamber having individual compartments of such predetermined size relative to each other as to effect a predetermined change in the amplitude to force ratio of the vibrations during transference therethrough.

2. Means for transferring sound vibrations to the organs of hearing, comprising a chamber adapted to have the sound vibrations imparted thereto and having a sound passage leading therefrom, the chamber being designed to cooperate through the sound passage with the auditory canal to form a dual chamber tuned as a whole to the desired frequency.

3. Means for transferring sound Vibrations from a vibratory body to the human ear, comprising a chamber adapted to have sound 'vibrations imparted thereto by said vibratory body and tapering toward a sound passage leading therefrom adapted to cooperate with the auditory canal to form a dual chamber tuned as a whole to the desired frequency.

4. Means for transferring sound 'vibra tions from a vibratory diaphragm to the human ear, comprising a chamber having a portion of its -wall formed by said diaphragm and adapted to have sound vibrations imparted thereto by said diaphragm and having a sound passa e leading therefrom adapted to termined size relative to each other as to transform'the amplitude to force ratio of the vibrations received from the said vibratory body substantially to that ratio suitable for the ear drum before imparting them to the latter. I

6. Means for transferring sound vibrations to the organs of hearing, comprising a chamber adapted to have the vibrations llllparted thereto and having a sound passage leading therefrom, the chamber being designed to cooperate through the sound passage with the auditory canal to form adual chamber having individual compartments of such-predetermined size relative to each other as to effect a predetermined change in the amplitude to force ratio of the vibrations during transference therethrough, and the dual chamber being tuned as a whole to the frequency of the sound vibrations.

In testimony whereof we aflix our signatures.

cooperate with the auditory canal to form a dual chamber tuned to the frequency of the sound vibrations employed.

5. Means for transferring sound vibra- WALTER HAHNEMAN N. HEINRICH HECHT.

BERN'HARD SETTEGAST. 

